Piston



y 23, 1940- F..w. CADDY 2,202,754

YISTON Filed Oct. 3, 1938 Inventor By W $5 4 F g Attorneys eateries May28,1940

oral) srArss PATENT OFFICE PISTON Fred W. Caddy,

twenty-five and one- Hibbing,

Minn., assignor or half per cent to William R. Spensley and twenty-fiveand one-half per cent to Andrew G. Anderson, both of Hibbing,

Minn.

Application October 3,

1' Claim.

Other objects of the invention are to provide a hydraulically expandedpiston of the aforementioned character which will be comparatively 15simple in construction, strong, durable, light in weight and which maybe manufactured at low cost.

All of the foregoing and still further objects and advantages of theinvention will become apparent from a study of the followingspecification, taken in connection with the accompanying drawing whereinlike characters of reference de'signate corresponding parts throughoutthe several views, and wherein: 25 Figure 1 is a view principally invertical section through an embodiment of the invention.

Figure 2 is a view in horizontal section, taken substantially on theline 2-2 of Fig. 1 with the connecting rod omitted. 36 Figure3 is adetail-view in perspective of the wrist pin.

Figure 4 is a vertical sectional view through the upper portion of theconnecting rod.

' Referring now to the drawing in detail, it will gs be seen that thereference numeral I designates a piston having the usual rings 2 mountedin the upper portion thereof. The skirt 3 of the piston l is split, asat 4, to permit expansion.

On diametrically opposite sides the skirt 3 of so the piston i hasformed integrally therein aligned bearings 5 and 6. Journalled in thebearings 5 and 6 is a wrist pin 1 which is mounted on a connecting rod8. The bearing 5 is closed at its outer end by the wall of the piston i,as at 9. as The bearing 6 is open at both ends and the outer end portionthereof is internally threaded to receive a removable closure plug Ill.

Mounted in the eye H of the connecting rod 8 is a bushing l2 whichreceives the wrist pin 1 5g and which has formed. in its innerperiphery, at an intermediate point, a groove 13. The bushing i2 isfurther provided with an opening M which establishes communicationbetween the groove 13 and an oil passage l5 in the connecting rod 8. asThe wrist pin 1 has formed therein, at an intermediate point, acircumferentially extending groove it which is in registry with thegroove 1938, Serial No. 233,120 (01. 309-19 l3 in the bushing l2.Extending longitudinally through the wrist pin I is a fluid passage 11.An opening or port iii in the wrist pin 1 establishes communicationbetween the groove l6 and the passage ll.

It is thou ht that the manner in which the invention functions will bereadily apparent from a consideration of the foregoing. The passage ISin the connecting rod 8 receives oil'under pressure from the usual oilpump of the engine. This oil passes through the opening it into thegrooves i3 and I6 and enters the passage ll through the port l8. The oilunder pressure then flows outwardly to the ends of the wrist pin 1 andenters the bearings 5 and. 6. The bearings 5 and 6, being closed, theoil cannot escape with the result that the skirt 2 of the piston l iscaused to expand. Although the piston I is free to rock on theconnecting rod 8 in the usual manner, construction and arrangement issuch that the passage II in the wrist pin 1 is in communication withthe,

passage in the connecting rod 8 at all times. The closure plug 10permits the insertion of the wrist pin 1 in the bearings 5 and 6 and, ofcourse, retains said wrist pin therein.

It is believed that the many advantages of a piston constructed inaccordance with the present invention will be readily understood andalthough a preferred embodiment of the device is as illustrated anddescribed, it is to be understood that changes in the details ofconstruction may be resorted to which will fall within the scope ofv 3the invention as claimed.

What is claimed is:

A piston comprising a split skirt, aligned bearings in said skirt, anintegral closure at the outer end of one of the bearings, a removableclosure plug threadedly mounted in the outer end portion of the other ofsaid bearings, a connecting rod having an oil passage therein, saidconnecting rod comprising an eye on one end, a bushing mounted in saideye, said bushing having an an- I nular groove in its inner peripheryand further. having an opening therein establishing communicationbetween the groove and the passage in the connecting rod, and a -wristpin mounted in the bushing and having its end portions journalled in thebearings, said wrist pin having a circumferentially extending groove atan intermediate point communicating with the groove in the bushing, saidwrist pin further having a longitudinal oil passage extendingtherethroughfrom end to end thereof and communicating with the bearings,said piston still further having a radial port therein establishingcommunication between the groove and the passage in said wrist pin. FREDW. CADDY.

